Today, in many modem manufacturing facilities, modular conveyor systems are extensively utilized to transport articles to and from various work stations during all stages of production. In recent years, manufacturers using production lines with conveyors as an integral component of the material handling system have realized reasonably significant gains in productivity and resource utilization. As a result, modular conveyor systems have become even more widely implemented and have been adapted to meet an even wider scope of the material handling needs of producers of a multitude of consumer and industrial goods. Therefore, the continual development of improved modular conveyors is necessary in order to keep pace with the demands and expectations of the users of such conveyors.
Thus, notwithstanding recent developments and advancements in conveyor designs, further improvements in the overall design and interaction of the plurality of individual links which make up the conveying surface are desired. One such needed improvement relates to elimination of undesirable gaps or openings which may exist in the conveying surface so as to better ensure a proper functioning and easy to clean conveyor. Furthermore, smooth link interaction is important, both while the links are moving from an expanded state to a compressed state, or vice-versa, as well as while in a fully or partially compressed state, such as during negotiation of a tight turn. Modular conveyors are often employed for transporting small articles, especially in the food industry, so that minimizing the gaps/openings is necessary for efficient support of the articles during conveying, which in turn minimizes downtime due to jamming, as well as cutting down on the waste and cleaning requirements.
In an effort to develop a modular conveyor assembly having the desired characteristics described above, prior art modular conveyors have routinely included links having forward and rearward extending segments that closely interconnect, and substantially close together especially while the conveying surface is in a compressed state. For example, U.S. Pat. No. 4,953,693 to Draebel, owned by the Assignee of the present invention, discloses a closed grid type conveyor assembly wherein there are minimal gaps/openings in the conveying surface once compressed. However, the possibility does exist for objects to fall into gaps/openings which may exist either prior to compression or while maneuvering through a turn. If so, these objects would prevent the links from functioning properly. Furthermore, the blunt ends of the links typical of prior art modular links are unable to lift upward any such foreign objects present in the gaps/openings.
Similarly, U.S. Pat. No. 5,174,439 to Spangler et al. also discloses a relatively closed grid type conveyor assembly having closely interconnected links. The link interconnection is enhanced with an undercut being provided on the forward extending portion of the link in order to provide clearance under the rearward extending portion of the next forward link. Nonetheless, there still exists the possibility for objects to fall into or become lodged in gaps/openings between the links while the conveying surface is in an expanded state or while making a turn. There would then be no way for the objects to be lifted out of the gaps/openings. While the undercut may enhance the interconnection of the links, the link end having the undercut is still somewhat blunt and would be unable to effectively lift upward any foreign objects inadvertently present between the links.
Another approach in the prior art adopted in an effort to improve material handling capabilities has been to construct an open grid type modular conveyor assembly capable of receiving spaced article engaging inserts. For example, U.S. Pat. No. 5,497,874 to Layne, also owned by the Assignee of the present invention, discloses such an open grid type conveyor assembly. While some openings are incidentally closed in this type of conveying surface where the inserts are developed, the elimination of other unnecessary openings along the conveyor is desirable. Additionally, the blunt ends of the links are similar to other prior art link ends and, thus, are unable to lift and free foreign objects present between the links.
Thus, it is clear that a need exists for a modular conveyor constructed from smooth interacting links for a wide range of sizes and types of articles. The closely interdigitating links have the capability of minimizing the possibility of small articles or objects from falling into or becoming lodged in gaps or openings on the conveying surface. Such a conveyor assembly would provide adequate support for the articles during conveying, as well as minimize waste, and ease cleaning and inspection requirements. In addition, it is also important that such a conveyor maintain the ability to effectively maneuver through a turn while maintaining the interdigitation. Another feature would be to include special side links that also minimize the possibility of small articles or similar objects falling through the conveyor in both the compressed or expanded state while retaining the ability of the conveyor to negotiate a tight turn.